The only reason for the recycling of cities is because it is based in a "parody of real world America"; therefore, the cities they've chosen continuously have been in real world America. I too would like to see the game return to London or some other place
but that's what computer mods are for since I highly doubt that Rockstar will go to other countries outside the US "until [we] have simulated the world outside".
I honestly like moderne time more than the past, so modern times for me. Never get tired of how R* parody America in modern times. The past was more like parodies following a specific movie or something. With modern times, I feel R* is able to capture the
"parody of America" they are always reaching for.
You have to admit though, Marwood, that seeing Liberty City, Vice City (I believe they will revisit it in VI), and San Andreas recycled does get a tad bit repetitive, right? True; they may be "updating the setting" but it's still based on the same cities.
I feel it's time for the series to return to London. I love gta4 but feel the series is getting a little stale with the same old cities (to me they all look roughly the same) and same accents over and over.....